Sources of drinking water can be naturally contaminated with biological impurities and can also be contaminated by chemical and other non-naturally occurring sources.
Some consumers choose bottle drinking water based upon convenience, and the perceived quality of bottled water. In actuality, single-use bottles pose health, sustainability, and environmental issues. The quality of bottled water can be affected by storage conditions. Up to one-third of bottled water can be contaminated by the water sources and the bottling facilities, as well as the use of plastic bottles. Commonly used plastics can leach hydrocarbon-based contaminants into drinking water, particularly when the plastic bottles are stored in direct sunlight or at elevated temperatures. More than three-fourths of plastic water bottles purchased are disposed and sent to land fills instead of being recycled. Bottled water also results in transportation costs and environmental effects because bottled water is often shipped from distant locations, including Poland Spring, Fiji and France. The increased purchase price and environmental costs of single-use plastic bottles raises sustainability issues.
Alternatives to bottled water include reusable bottles, generally designed for sporting and/or camping purposes. Reusable bottles often rely on home or office filtration systems as a refilling source. Other available water supplies vary in quality. Public water supplies can have chlorine and other undesirable tastes, often from metallic conduits. Water supplies can also be affected by the natural source, including hard water obtained from an aquifer or river flowing through limestone. Water sources purified by reverse osmosis systems can be flat and taste badly to consumers. Water derived from wells or poorly maintained storage tanks may also contain contaminants.
Water purification removes undesirable chemicals, biological contaminants, suspended solids, and gases from contaminated water to make the water suitable for drinking Purification can include physical processes such as filtration, sedimentation, and distillation, biological processes such as slow sand filters or biologically active carbon, chemical processes such as flocculation and chlorination and the use of electromagnetic radiation such as ultraviolet light.
Some portable water filters and purifiers rely on pressure differential, as developed by suction from the mouth piece and/or pressure on the bottle (e.g., squeezing the bottle) for water flow. Other portable systems rely on straws through which the water must be drawn. In these systems, water is purified as it flows from the container bottom to the top. Users must exert a large force (by sucking or squeezing) to draw the water through the purifier. Other portable water purifiers rely on filters and purifiers configured as cartridges that are mounted in the cap of a sports bottle.
Personal sports bottles are used for carrying water and other liquids for quick hydration during sporting activities such as running, cycling, hiking, tennis, golf, hockey, and the like. The cost and inconvenience of accessing filtered water can discourage consumption of sufficient quantities of fluids to adequately hydrate the athlete.